Longwall mining systems are used to mine a block of coal or other ore called a longwall block. The longwall block includes a coal face (or ore face) from which coal (or ore) is removed. Two roadways, a maingate roadway and a tailgate roadway, run along the sides of the longwall block and orthogonal to the coal face. The longwall mining system includes powered roof supports to support roof and overlying rock above the longwall system. A longwall shearer moves along the coal face of the longwall block, shearing coal from the coal face and onto an armored face conveyor (AFC). The armored face conveyor extends along the coal face and transports coal towards the maingate roadway. When coal has been hauled to the maingate roadway, a beam stage loader (BSL) connected to the armored face conveyor transfers the coal from the armored face conveyor, through a 90 degree turn, and onto a belt conveyor positioned along the maingate roadway. After the longwall shearer shears off a layer of the coal face, the longwall mining system moves forward to shear the next layer.
As the longwall mining system operates it is common for the whole structure to migrate or creep such that the distance between the beam stage loader and the walls of the maingate roadway decreases. This migration or creep of the longwall equipment may cause difficulty in gaining access to the longwall by personnel. Further, this migration or creep may also result in the longwall equipment rubbing against the maingate equipment and the walls of the maingate roadway causing damage to the longwall equipment.